1. Field of the Invention
The present application generally relates to a shift actuator, a vehicle, and a method of assembling a vehicle.
2. Description of the Related Art
A motorcycle is popular type of vehicle. Motorcycles typically comprise an engine and a transmission. The transmission alters a rotational speed of a crankshaft of the engine while transmitting power from the crankshaft to a drive wheel. The transmission can comprise a shift mechanism, a main shaft, a drive shaft and a plurality of speed change gear combinations. A clutch mechanism can be positioned between the engine and the transmission such that rotation of the transmission can be stopped while the gear combination is changed.
At least one motorcycle has implemented an automated manual transmission mechanism (AMT mechanism) that automates the gear combination shifting operation. Such a transmission is described in JP-A-2006-017221. The AMT mechanism includes a shift actuator that drives a shift mechanism and a shift-power transmitting mechanism that connects the shift actuator and the shift mechanism. The shift-power transmitting mechanism transmits forces from the shift actuator to the shift mechanism.
The shift actuator includes a motor, which acts as a drive source. The shift actuator also includes a shift potentiometer. The shift potentiometer detects a rotational angle of the motor. The shift actuator determines the speed change position of the shift mechanism based the output of the shift potentiometer.
The shift mechanism is capable of rotating in a forward direction and a reverse direction from a reference position (i.e., a neutral position). Rotation of the shift mechanism from the reference position effects a change in the selected gear combination. Thus, during assembly of the motorcycle, the shift actuator is calibrated to match the reference position during production at a factory, during maintenance or the like. For instance, the shift power transmitting mechanism is adjusted such that it is in the reference position when the output of the shift potentiometer is a predetermined voltage value.
Calibration of the shift actuator by adjusting the position of the shift power transmitting mechanism is a manual operation that requires the individual performing the calibration to repeatedly confirm the output voltage value of the potentiometer. Calibration therefore is complicated, assembly of the motorcycle is difficult and maintenance of the assembled vehicle is tedious.
Accordingly, one aspect of the present invention relates to simplifying the assembly of the vehicle through improvements in the shift actuator and related vehicle components.